package collection;
import java.util.ArrayList;
import java.util.Collection;

public class CollectionDemo3 {
    public static void main(String[] args) {
        Collection c = new ArrayList();
        //c.add(123); //c.add(Integer.valueOf(123));此处自动装箱了
        Point p = new Point(1,2);
        c.add(p); //将p添加到集合c中-----将引用(地址)装到了c中
        System.out.println(p); //(1,2)
        System.out.println(c); //[(1,2)]

        p.setX(100);
        System.out.println(p); //(100,2)
        System.out.println(c); //[(100,2)]
    }
}
